A column of black smoke billows out of the complex. Photograph:( Twitter )
SpaceX's Falcon 9 rocket exploded at the Kennedy Space Centre in Florida, multiple media reports said.
It remains unclear at the moment whether there have been casualties. But the intensity of the explosion rocked buildings "several miles away", according to The Verge.
Emergency services have however said there is no threat to the public.
Although the cause of the blast remains unknown, NASA officials said it occurred during a static fire test of the rocket's engines.
SpaceX, a company owned by Tesla Motors CEO Elon Musk, intends to send people to Mars within the next two decades.
(WION with inputs from agencies)